Automatic bell-switch.



A'. P. KAISER.

AUTOMATIC BELL SWITCH.

APPLICATION FILIJD MAYZQ, 1909.

1,017,101. Patented Feb. 13, 1912,

Tim. L.

Wanna ALFRED FREDERICK KAISER, OF DETROIT, MICHIGAN.

AUTOMATIC BELL-SWITCH.

Specification of Letters Patent.

Patented Feb. 13, 1912.

Application filed May 29, 1909. Serial N 0. 499,123.

To all whom it may concern Be it known that I, ALFRED F. KAISER, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented a new and useful Improvement in Automatic Bell-Switches, of which the following is a specification.

This invention relates to an automatic bell switch, the object of the invention being to ring a bell, or to sound some other audible alarm when a door is opened, the alarm continuing during the period the door remains open, unless cut off by means of an ordinary hand switch.

The invent-ion consists in the novel features of construction hereinafter described, pointed out in the claim, and shown in the accompanying drawings, in which:

Figure 1 is a sectional view through a door casing and door showing my switch in position. Fig. 2 is a plan view of the lower side of the switch. Fig. 3 is a plan of the back, and Fig. 4 is a side elevation.

In constructing the device, I provide a block 1, the rear upper face of which is provided with intersecting oblique grooves 2 which connect binding posts 3 placed adjacent the corners of the block. Electrical conductors 4 run through these grooves connecting the binding posts and also extend from two of said binding posts to suitable line wires, a bell or other signal device, not shown, being included in the line wire circuit. An angled plate 6 has laterally projecting lugs 6 struck out from the plate on the line of its bend and these lugs are journaled in bearings formed by screw eyes 5 carried by the inner edge of the block 1. On the front face of the block are metal contact plates 7 which are in contact with the adjacent binding post 3 and the space between the plates 7 is bridged by the angled plate 6 when the door is open.

The device is set in position by setting the block 1 in the top of the door casing, its front face being downward and the angled plate 6 will have one portion slanting downwardly and the other portion bearing upon the plate 7 and bridging the space between them, gravity holding the angled plate in this position. A circuit is therefore established between the two plates 7 and between the conduct-ing wires 4, thus completing the circuit through the line wires. When a door 8 swings into closed position it will strike the slanting inclined portion of the plate 6 and will rock the plate in its bearings, lifting the depending portion which when the door is closed will rest in a suitable slot in the top of the door. The lifting of this portion of the plate will cause that portion bridging the space between the plates 7 to swing downwardly away from the plates, thus breaking the circuit. As soon as the door is opened, the weight of the free end of the plate will cause it to drop to its normal position, and in order to reduce the weight of the end portion of the plate closing the circuit, I cut away opposite sides of the said plate and also make it of less length than the other portion, the lugs not being arranged opposite the true center of the plate. will be obvious therefore that the circuit will be completed as soon as the door swings open and will remain completed at this point until the door is again closed.

What I claim is:

The combination with a door frame and a swinging door, contact plates carried by the top of the door frame, said plates forming part of an electric circuit and being.

spaced apart, and an angled plate pivoted adjacent the contact plates, one portion of said angled plate being heavier than the other, the heavier portion normally hanging downwardly in position to be swung into a horizontal plane by the closing of a door, the lighter portion of the plate bearing against the contact plates when the heavier portion is in normal position.

ALFRED FREDERICK KAISER.

Witnesses J ULIUS BONNINGHAUSEN, LILLIAN SHILLING.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of ZPatents. Washington, I). C. 

